Hyster Forklift HR 45-41L

Position the load holding valve on the derricking cylinder.

Install the four capscrews that fasten the load holding valve onto the derricking cylinder.

Remove caps and connect the hydraulic lines to the load holding valve according to the identification tags made during removal.

Connect the electrical wires to the load holding valve according to the identification tags made during removal.

Warning: Do not try to locate hydraulic leaks by putting hands on pressurized hydraulic components. Hydraulic oil can be injected into the body by pressure.

Caution: Never start the engine with closed shutoff valves. Open the shutoff valves before starting the engine to prevent damage to hydraulic components.

Start the engine and operate the hydraulic system. Check that functions of the load holding valve work correctly. Check for any leaks.

Did the load holding valve work correctly?

NOTE: Only use plugs that have been cleaned in solvent.

NOTE: In the event that seals are missing, check manifold for missing seals and remove.

NOTE: Cartridge valves are not field serviceable with exception of external seals and electrical solenoids. In event of a defective component, completely replace valve.

NOTE: Check load holding valve for cracks. If there are cracks in load holding valve, the load holding valve must be replaced.

The valve seals are serviceable parts of the load holding valve. Use the following procedures for repair:

Unscrew the cartridge valve from the load holding valve. See Figure 9.

Check that all seals are attached to cartridge valve.

Install a temporary plug in place of cartridge valve.

Upload a photo of the disassembled circuit

!WARNING: Cleaning solvents can be flammable and toxic and can cause skin irritation. When using cleaning solvents, always follow the solvent manufacturer’s recommended safety precautions.

Compressed air can move particles and cause injury to the user or to other personnel. Make sure compressed air path is away from all personnel. Wear eye protection.

Clean cartridge valve or switch in solvent and carefully dry the parts with compressed air.

Inspect the bores for damage. If there are scratches or other damage, the manifold must be replaced.

Inspect the fittings, O-rings, and check valves for damage.

Sign off on the cab manifold maintenance

!WARNING: Lower boom completely before working on control valve or hydraulic system. The boom can lower suddenly and cause injury if the boom is not lowered. This procedure will make sure that the boom cannot lower suddenly and cause injury or death.

Place the truck on a solid and level surface.

Lower boom and close the shutoff valves at the bottom of the hydraulic tank platform.

Remove covers on the topside of the frame.

NOTE: The pump assembly has two suction hoses and two high-pressure lines.

NOTE: When disconnecting the suction hose at the variable displacement pump, raise hose quickly and install a plug to avoid leakage from the hose.

Disconnect suction hose at the variable displacement pump.

Disconnect high-pressure line at the outlet port on the pump side of the variable displacement pump. Raise the end of the line above hydraulic tank platform until a plug is installed in the line.

Position the load holding valve on the derricking cylinder.

Install the four capscrews that fasten the load holding valve onto the derricking cylinder.

Remove caps and connect the hydraulic lines to the load holding valve according to the identification tags made during removal.

Connect the electrical wires to the load holding valve according to the identification tags made during removal.

Warning: Do not try to locate hydraulic leaks by putting hands on pressurized hydraulic components. Hydraulic oil can be injected into the body by pressure.

Caution: Never start the engine with closed shutoff valves. Open the shutoff valves before starting the engine to prevent damage to hydraulic components.

Start the engine and operate the hydraulic system. Check that functions of the load holding valve work correctly. Check for any leaks.

Did the load holding valve work correctly?